Video Missing Captions — WCAG Failure
WAVE (Error: Missing captions), axe DevTools (rule: video-captions for <video> elements), Lighthouse (partial detection), Pa11y. Note: automated tools detect missing <track> elements but cannot verify caption quality.
Why it matters
Approximately 15% of American adults (37.5 million people) report some trouble hearing, and 1 million Americans are functionally deaf. For these users, video content without captions is completely inaccessible — they cannot understand the audio, follow dialogue, or access information conveyed only through speech. Captions also benefit many non-disabled users: people watching in noisy environments, non-native speakers learning the language, users in quiet public spaces, and people who find reading along improves comprehension. From a legal standpoint, WCAG 1.2.2 (Captions for prerecorded content) is Level A — the minimum accessibility requirement. Several major ADA lawsuits have focused specifically on uncaptioned video content, including cases against Netflix (settled 2012, $755,000), and multiple university systems for uncaptioned course videos. Auto-generated captions alone do not satisfy WCAG when they contain errors — captions must be accurate.
Symptoms — what you'll see
If your site has this problem, you may observe any of the following:
- Videos play with audio but no caption track is available
- Videos have auto-generated captions that are inaccurate or unreviewed
- Video content contains important information not available in text elsewhere on the page
- Live-streamed video has no live captioning service
- WAVE flags "Missing captions" or "No captions" for video elements
- YouTube embeds using default auto-captions that are not corrected
- Video background or hero videos that convey important audio content
Common causes
- Assuming YouTube auto-captions are sufficient (they frequently contain errors)
- Adding video to sites without an established captioning workflow
- Video production teams that do not consider accessibility in post-production
- Third-party video platforms (Wistia, Brightcove, JW Player) not configured to display available captions
- Background hero videos treated as "decorative" when they contain important audio
- Live streaming without planning for real-time captioning
- Webinar recordings published without adding captions post-production
How to fix it
- 1Inventory all video content on your site: hosted video, YouTube embeds, Vimeo embeds, and live streams.
- 2For HTML5 <video> elements: add a <track kind="captions" src="captions.vtt" srclang="en" label="English" default> inside the video element.
- 3Create WebVTT (.vtt) caption files: a timed text format that syncs captions with video.
- 4For YouTube: edit each video in YouTube Studio > Subtitles > add or correct captions (do not use unreviewed auto-captions alone).
- 5For Vimeo: upload SRT or VTT caption files via the video settings in Vimeo.
- 6Review and correct any auto-generated captions for accuracy — auto-captions frequently fail on technical terms, proper nouns, and accented speech.
- 7For live video: partner with a live captioning service (AI or human) and enable captions on your streaming platform.
- 8Captions must include dialogue, speaker identification, and meaningful non-speech sounds (e.g., [applause], [laughter]).
Code example
<!-- BROKEN: video with no captions -->
<video controls width="800">
<source src="product-demo.mp4" type="video/mp4">
Your browser does not support video.
</video>
<!-- BROKEN: YouTube embed with auto-captions only (no custom captions added) -->
<iframe src="https://www.youtube.com/embed/VIDEO_ID"
title="Product demo video">
</iframe><!-- FIXED: video with captions track -->
<video controls width="800">
<source src="product-demo.mp4" type="video/mp4">
<track
kind="captions"
src="/captions/product-demo-en.vtt"
srclang="en"
label="English captions"
default
>
Your browser does not support video.
</video>
<!-- FIXED: YouTube embed with captions enabled + transcript link -->
<iframe
src="https://www.youtube.com/embed/VIDEO_ID?cc_load_policy=1&cc_lang_pref=en"
title="Product demo video — captions available"
allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope"
allowfullscreen>
</iframe>
<!-- Provide transcript as alternative -->
<details>
<summary>Video transcript</summary>
<p>Full transcript text here...</p>
</details>How to test your fix
After applying the fix, verify it works using these testing steps:
- Identify all video content across your site using a site crawler or manual review.
- For each video, play it and check if a caption track is available and active.
- Verify caption accuracy: watch with sound off and captions on — does the text match the spoken content?
- Check that captions include speaker identification for multiple speakers.
- Inspect HTML5 video elements for <track kind="captions"> child elements.
- Run axe DevTools and check for "video-captions" rule violations.
- Run WAVE and check for video-related errors.
- For YouTube: go to each video > Settings gear > Subtitles/CC — verify captions are available and are manually reviewed, not just auto-generated.
Frequently asked questions
Are YouTube's automatic captions enough to meet WCAG?+
No. Auto-generated captions frequently contain errors, especially for technical vocabulary, proper nouns, accented speech, and fast talkers. WCAG requires captions to be accurate. Auto-captions can be a starting point, but you must review and correct them in YouTube Studio before they satisfy WCAG 1.2.2. Unreviewed auto-captions have been cited as insufficient in ADA lawsuits.
What is the difference between captions and subtitles?+
Subtitles assume the viewer can hear — they translate spoken dialogue into another language. Captions assume the viewer cannot hear — they transcribe all audio content including dialogue, speaker identification, and meaningful sounds like [door slams] or [background music]. WCAG requires captions (for deaf users) not just subtitles.
Do decorative background videos need captions?+
If a background video is purely decorative (no important information in the audio track, often muted by default), it is exempt from WCAG 1.2.2. However, if the video has audio that conveys any content, or if the video itself conveys important information to sighted users, accessibility alternatives (captions, audio description, or text alternative) are required.
What caption file format should I use?+
WebVTT (.vtt) is the standard for HTML5 video and is supported by all modern browsers natively. SRT (.srt) is widely supported by video platforms (YouTube, Vimeo) and can be converted to VTT. SRT lacks some VTT features like styling and positioning. For production use, create VTT files for your site and SRT for platform uploads.
Do we need an audio description track as well as captions?+
WCAG 1.2.3 (Level A) and 1.2.5 (Level AA) require audio descriptions for prerecorded video when the video contains important visual information not conveyed in the audio track. Examples: on-screen text, visual demonstrations, or scene information essential for understanding. If all important information is already described in the audio (narrated clearly), a separate audio description may not be needed.